<template>
  <div class="goods">
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li v-for="(item,index) in goods" class="menu-item" :class="{'current':currentIndex===index}"
            @click="selectMenu(index, $event)">
          <span class="icon text border-1px" v-show="item.type > -5" :class="classMap[item.type]">{{item.name}}</span>
        </li>
      </ul>
    </div>
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li v-for="item of goods" class="food-list food-list-hook" :key="item.name">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li @click="selectFood(food, $event)" v-for="food in item.foods" class="food-item border-1px" :key="food.name">
              <div class="icon">
                <img width="57" height="57" :src="food.icon">
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span><span>好评率{{food.rating}}</span>
                </div>
                <div class="price">
                  <span class="now">￥{{food.price}}</span><span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cart-control @cartAdd="drop" :food="food"></cart-control>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <shop-cart ref="shopCart" :selectFoods="selectFoods" :deliveryPrice="seller.deliveryPrice" :minPrice="seller.minPrice"></shop-cart>
    <food :food="selectedFood" ref="foodele"></food>
  </div>
</template>

<script>
  import axios from 'axios'
  import BScroll from 'better-scroll'
  import ShopCart from "../shopcart/ShopCart";
  import CartControl from '../cartcontrol/CartControl'
  import Food from "../food/Food"
  const ERR_OK = 0;
    export default {
        name: "Goods",
        components: {
          ShopCart,
          CartControl,
          Food
        },
        data () {
          return {
            goods: [],
            listHeight: [],
            scrollY: 0,
            seller: {},
            selectedFood: {}
          }
        },
        computed: {
          currentIndex() {
            for (let i = 0; i < this.listHeight.length; i++) {
              let height1 = this.listHeight[i]
              let height2 = this.listHeight[i+1]
              if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
                return i;
              }
            }
            return 0;
          },
          selectFoods() {
            let foods = []
            this.goods.forEach((good) => {
              good.foods.forEach((food) => {
                if (food.count) {
                  foods.push(food)
                }
              })
            })
            return foods
          }
        },
        methods: {
          getGoodsInfo() {
            axios.get('/api/data.json').then(this.handleGetDataSucc)
          },
          handleGetDataSucc (res) {
            const data = res.data
            this.seller = data.seller
            if (data.errno === ERR_OK && data.goods) {
              this.goods = data.goods
              this.$nextTick(() => {//异步执行
                this._initScroll()
                this._calculateHeight()
              })
            }
          },
          _initScroll() {
            this.meunScroll = new BScroll(this.$refs.menuWrapper, {
              click: true
            })
            this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
              click: true,
              probeType: 3
            })
            this.foodsScroll.on('scroll', (pos) => {
              this.scrollY = Math.abs(Math.round(pos.y))
            })
          },
          _calculateHeight() {
            let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
            let height = 0
            this.listHeight.push(height)
            for (let i = 0; i < foodList.length; i++) {
              let item = foodList[i]
              height += item.clientHeight
              this.listHeight.push(height)
            }
          },
          selectMenu(index, event) {
            if (!event._constructed) {
              return
            }
            let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
            let el = foodList[index]
            this.foodsScroll.scrollToElement(el, 300)
          },
          selectFood(food, event) {
            if (!event._constructed) {
              return
            }
            this.selectedFood = food
            this.$refs.foodele.show()
          },
          drop (ele) {
            // 体验优化，异步执行下落动画
            this.$nextTick(() => {
              this.$refs.shopCart.drop(ele)
            })
          }
        },
        mounted() {
          this.getGoodsInfo()
        },
        created() {
          this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee']
        },
    }
</script>

<style lang="stylus" scoped>
  @import "~@/common/stylus/mixin.styl"
  .goods
    display: flex
    position: absolute
    top: 174px
    bottom: 46px
    width: 100%
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display table
        height: 54px
        width: 56px
        padding: 0 12px
        line-height: 14px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          background: #fff
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          border-1px(rgba(7, 17, 27, 0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147, 153, 159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7, 17, 27)
          .desc, .extra
            line-height: 10px
            font-size: 10px
            color: rgb(147, 153, 159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240, 20, 20)
            .old
              text-decoration: line-height
              font-size: 10px
              color: rgb(147, 153, 159)
          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 12px
</style>
